MUD: FIM Motocross World Championship is a racing game that focuses on action rather than simulation. It is licensed and features the original teams, vehicles, courses, and athletes from the FIM Championship.
The heart of the game is the Mud World Tour, which is essentially a career mode. By being successful at events (such as normal races with 16 athletes, checkpoint races, elimination races, head-to-head races, or freestyle/trick events), the player earns money that can be invested into improving the driver's statistics (endurance, instinct, mobility, and strength), equipment (such as energy drinks that give a speed boost), next events, switching to a better team, or unlocking other drivers. Each driver has a specialization for certain events, resulting in more prize money.
The game also features single races, playing the Championship (either MX1, MX2, or custom), or participating in freestyle events where the player needs to perform stunts to gain points. In regular races, tricks play only a small role as there is only one trick to perform: when the bike is in the air, the player can press a button with the right timing to execute a scrub and speed boost; if done incorrectly, it results in a whip with no advantages. Multiplayer allows for races with up to 12 players.
In the Xbox 360 version of the game, there are more machines available compared to the PS Vita version, which has half as many machines in each race.